Abrasive detergent composition



- solubilized by sodium,

Patented Jan. 1, 1952 2,581,278 vABRASIVE DETERGENT COMPOSITION Casimir J. Munter, St. Clair Township, Allegheny County, Pa., assignor to Hall Laboratories, Inc.,

Pittsburgh, Pa., 2. corporationoif No Drawing.

Original an Pennsylvania plication June 1, 1945.,

Serial No. 597,157, now Patent No. 2,494,827,- dated January 17, 1950. Divided and this application October 22, 1949, Serial No. 123,106'

7 Claims.

This invention relates to improved detergents suitable for personal and other uses, and more particularly to compositions containing waterinsoluble crystalline alkali-metal metaphosphate. This application is a division of my copending application Serial No. 597,157 filed June 1, 1945, for Abrasive Detergent Compositions, now Patent 2,494,827 granted January 17, 1950.

An object of my invention is to provide a detergent or cleanser which is non-hygroscopic and which can be readily packed in ordinary containers without taking special precautions to prevent moisture absorption.

Another object of the invention is to provide a detergent composition that is initially freefiowing and will remain free-flowing over long periods of time so that it can be readily dispensed from the ordinary type of dispensing mechanism without difficulty.

A still further object-of my invention is to provide a detergent composition containing soap which has an improved lathering power and improved detergent qualities, and which will be non-irritating to the skin.

The glassy alkali-metal metaphosphates also known as alkali-metal phosphate glasses are widely known for their effectiveness in hard water because of their ability to soften water on the sequestration principle as disclosed in Hall Patent Re. 19,719. The glassy phosphates are hygroscopic and for that reason are not suitable for mixing with soap, in powder, flake, or bar form, or in liquid soaps, because of rehydration of the phosphate wholly or in part to orthophosphate with resultant loss of sequestering power and a deleterious effect on the soap because of the development of acidity.- The glassy alkali-metal metaphosphates being hygroscopic, the moisture absorbed thereby would naturally destroy the free-flowing qualities of'a dry mixed detergent composition containing these materials and soap containing water.

I have found that desirable detergent compositions can be prepared by using the water-insoluble crystalline metaphosphates since these materials are not hygroscopic and consequently a finely divided free-flowing composition will remain substantially is used. It has been found that the water-insoluble crystalline sodium metaphosphates can be solubilized by potassium, lithium, and ammonium compounds and that the water-insoluble, crystalline potassium metaphosphates can be lithium, and ammonium salts. Therefore, if I prepare a detergent com unchanged in form until it position containing a sodium soap of a fatty acid, I use a water-insoluble crystalline potassium metaphosphate or a mixture of this potassium salt and the water-insoluble crystalline sodium metaphosphate. If I employ a potassium soap of a fatty acid in my detergent composition, I use the water-insoluble crystalline sodium metaphosphate or I may use a mixture of this salt with the water-insoluble crystalline potassium metaphosphate. In both cases, the alkali-metal of the soap acts in such a way as to solubilize the normally water-insoluble phosphates.

In ordinary detergent compositions which employ alkaline softening compounds that precipitate the hardness soap lather is quickly broken by the formation of calcium and magnesium soaps which :are water-insoluble. By solubilizing the water-insoluble phosphates used in my composition, water softening is obtained and it is believed that water-soluble complexes are formed with the hardness minerals of the water. There is no precipitation of the insoluble metallic soaps and full effectiveness of the detergents is made possible.

By using from about 2% to about 40% by weight of a water-insoluble crystalline alkalimetal metaphosphate or mixtures thereof in my detergent compositions, I have found that certain unexpected beneficial results are obtained. For example, since these phosphates are not instantaneously solubilized when the detergent is use, a certain abrasive action is noted even when I use only those amounts of phosphate required for sequestration of hardness, that is to say, 10% or less by weight. The insoluble phosphate provides a combined abrasive and sequestering action, the abrasive action diminishing as the phosphate solubilizes and the sequestering action increasing as solubilizing proceeds. In the presence of the solubilized phosphates, the detergents seem to exhibit improved dispersing properties and the viscosity of the soap lather seems to be considerably greater.

The crystalline water-insoluble sodium metaphosphates may be prepared by combining phosphoric anhydride and any suitable sodium alkali in proper proportions to produce mono-sodium orthophosphate. The mono-sodium orthophosphate is dehydrated at a temperature from about 300 to 500 C. producing the insoluble crystalline sodium metaphosphate. A process for producing insoluble sodium metaphosphate is disclosed by Taylor and Erdman in U. S. Patent minerals from water, the- No. 2,356,799. The insoluble crystalline potassium metaphosphate may likewise be produced by dehydrating mono-potassium orthophosphate in a temperature range from 350 to 800 C. or by combining phosphoric anhydride and an appropriate potassium alkali to produce mono-potassium orthophosphate which may be dehydrated at a temperature of from about 350900 C. thereby producing the crystalline potassium metaphosphate. The potassium metaphosphate may also be produced by melting mono-potassium orthophosphate at a temperature above 900 C. and allowing it to crystallize as it cools. In both the crystalline sodium and potassium metaphosphate the ratio of MzozPzOs is 1:1, M being the alkali-metal of the oxide.

The abrasive action of my detergent composition I obtain from the insoluble phosphates themselves and I may use as much as 40% by weight of the total mixture of these insoluble phosphates. Where I add both the water-insoluble crystalline sodium metaphosphate and the water-insoluble crystalline potassium metaphosphate to a detergent composition by which I desire to obtain abrasive about 2%l0% by weight of potassium metaphosphate and about 30%-40% by weight of the sodium metaphosphate. The potassium metaphosphate will solubilize part of the sodium metaphosphate while the balance of the sodium undissolved and will the commetaphosphate will remain produce the desired abrasive effect in position.

In preparing my detergent composition I may use from about 20% to about 60% by weight of any appropriate soap of a fatty acid. For the dry mixtures which may be used in a dispensing mechanism or direct from the container in which they are packed, I prefer to use a finely-divided soap in granulated form, although beads, ribbon,

chips, or powder may be satisfactory. In some of my compositions I use an essentially anhydrous soap, whereas, in others the soap may contain about 10% of moisture. Although I prefer to use a soap having a titre in the range of from 20-30 for my dry mixes, I may employ a soap having a lower titre if the final product is to be used only in cold water where quick lathering is desired. In mixtures which are in paste form, I prefer to employ a soft soap containin about 4.0%-50% moisture. In most mixes, I use a sodium soap but in others, a potassium soap is employed. The soaps which are used in my paste detergent composition have a lower titre than those which are used in my free-flowing dry mixtures.

In some of my detergent compositions I may use from about 3% to about 15% by weight of a supplemental water softening agent, this agent acting not only as a water softener but also as a mild alkali. Such phosphates as the pyrophosphates and tripolyphosphates, for example, sodium tripolyphosphate, provide additional water softening and supplemental alkalinity. If anhydrous tetrasodium pyrophosphate is used, the amount thereof may vary from 5% to 10% by weight, and, if the anhydrous tetrapotassium pyrophosphate is employed, the percentage by weight may be from about to 10%. Where the sodium tripolyphosphate is employed, the percentage by weight may be from to 15% of the weight of the composition. By using small amounts of these supplemental softening agents, I may reduce somewhat the amount of crystalline watersinsoluble alkali-metal phosphate which is effect, I may use from considerably greater in cost than the supplemental softening agents themselves.

To most of the forms of detergent composition I prefer to acid from about 5% to about 10% by weight of an alkali-metal buffering agent for the control of pI-I value. Such mild alkaline salts as sodium borate (borax), modified soda, sodium bicarbonate, and soda ash can be employed in small quantities. All of these compounds have mildly alkaline characteristics and since the crystalline insoluble metaphosphates do not impart alkalinity to the composition, these buffering agents are desirable in most instances.

In some cases it may be desirable to incorporate from about 0.5% to about 5.0% by weight of an antiseptic agent in the detergent composition.

Such antiseptic agents as sodium n-chloroparatoluenesulfonamid, commonly known as chloramine-T, n-dichloroparatoluenesulfonamid, commonly known as dichloramine-T, and sodium perborate, can be used. All of these agents have an effect in destroying certain bacteria which may be present on the surface that is to be washed by the detergent composition. Certain stabilizers of an organic nature should be included in the detergent composition where rancidity of the soap is likely to develop. Such compounds as carvacrol and eugenol are suitable in very small amounts, about 0.1% being sufficient. Perfumes may also be added to any of these compositions where desired.

The following are typical examples of detergent compositions which may be prepared in accordance with my invention:

Example I Percent Sodium soap (20-80 mesh, 10% moisture) 55.0 Sodium metaphosphate (crystalline-100 Abrasive characteristic derived from undissolved NaPOz crystalline Example II Percent Potassium soap (soft-40% water) 55.0 Sodium metaphosphate (crystalline 100 mesh) 40.0 Potassium pyrophosphate 5.0

Suitable as mechanic's handsoap or for cleansing painted surfaces. Abrasive efiect obtained from undissolved NaPOs; crystalline K4P2Ow added for increased alkalinity and water softening power.

The soap content of the detergent composition may be varied in amount by weight from about 20% to 60% and the soap may be an alkali-metal I soap of a fatty acid which is soluble in the composition when wetted with water. The total amount of the water-insoluble sodium and potassium metaphosphates may be as much as about 40% by weight of the detergent mixture, with potassium metaphosphate content varying from 2%-10% by weight of the detergent composition. I may modify compositions containing sodium pyrophosphate by substituting for the pyrophosphate other supplemental water softening agents such as sodium tripolyphosphate (NasPaOm) in amounts varying from 5% to by weight of the detergent composition, and alkali-metal buffering agents for the control of pH value, such as sodium borate (borax) modified soda, sodium bicarbonate, and soda ash.

I claim:

1. A finely-divided free-flowing detergent composition consisting essentially of from about 40%-60% by weight of a sodium soap, from about %40% by weight Of finely-divided water-insoluble crystalline sodium metaphosphate, from about 2%10 by weight of finely-divided crystalline potassium metaphosphate and from about 5%-10% by weight of anhydrous tetrasodium pyrophosphate, said detergent when used having both water softening and abrasive properties resulting from that portion of the crystalline sodium metaphosphate which is not dissolved while the product is being used.

2. As a new composition of matter a detergent in paste form which consists essentially of from about 40%-60% by weight of a soft potassium soap of a fatty acid, from about %-45% by weight of water-insoluble crystalline sodium metaphosphate and from about 3%-10% by weight of water-soluble crystalline potassium pyrophosphate, said composition exhibiting an abrasive effect due to that portion of the crystalline sodium metaphosphate remaining in an undissolved state while the product is being used.

3. An abrasive soap composition which is freeiiowing and substantially non-hygroscopic and consisting essentially of the following constituents intimately mixed and in substantially the proportions stated by weight: (a) water-soluble alkali-metal soap of a fatty acid, 20% to 60%, b) water-insoluble crystalline alkali-metal metaphosphate, 2% to (c) an alkali-metal alkaline reacting salt, 5% to 10%, said salt being capable of buffering the pH of the composition when it is wetted with water, the alkali-metal of at least one of said constituents (a) and (c) being such as will solubilize the water-insoluble alkali-metal metaphosphate when the said composition is wetted with water.

4. An abrasive soap composition which is freeflowing and substantially non-hygroscopic and consisting essentially of the following constituents intimately mixed and in substantially the proportions stated by weight: (a) Water-soluble alkali-metal soap of a fatty acid, 20% to (b) water-insoluble crystalline alkali-metal metaphosphate, 2% to 40%, (c) a water-soluble alkalimetal alkaline reacting crystalline phosphate, 3% to 15%, said phosphate having water softening properties, and (d) an alkali-metal alkaline reacting pH buffering salt other than (c), 5% to 10%, the alkali-metal of at least one of said constituents (a), (c), and (d) being such as will solubilize the water-insoluble alkali-metal metaphosphate when the abrasive composition is wetted with water.

5. A composition according to claim 3 in which at least a part of constituent (b) is a water-insoluble crystalline potassium metaphosphate constituting from about 2% to about 10% by weight of the composition.

6. A composition according to claim 3 containing a small amount of an organic stabilizer for preventing rancidity of the soap while in storage.

7. An abrasive soap composition which is freefiowing and substantially non-hygroscopic and consisting essentially of the following constituents intimately mixed and in substantially the proportions stated by weight: (a) an alkali-metal soap of a fatty acid, 20% to 60%, (b) a mixture of water-insoluble crystalline sodium metaphosphate and water-insoluble potassium metaphosphate, 2% to 40%, (c) an alkali-metal alkaline reacting salt, 5% to 10%, said salt being capable of buffering the pH of the composition when wetted with water, the alkali-metal soap of (a) being soluble in the presence of (b) and (0) when the mixture is wetted with water.

CASIMIR J. MUNTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Oil, Paint & Drug Reporter-June 28, 1943, pg. 52. 

1. A FINELY-DIVIDED FREE-FLOWING DETERGENT COMPOSITION CONSISTING ESSENTIALLY OF FROM ABOUT 40%-60% BY WEIGHT OF A SODIUM SOAP, FROM ABOUT 30%-40% BY WEIGHT OF FINELY-DIVIDED WATER-INSOLUBLE CRYSTALLINE SODIUM METAPHOSPHATE, FROM ABOUT 2%-10% BY WEIGHT OF FINELY-DIVIDED CRYSTALLINE POTASSIUM METAPHOSPHATE AND FROM ABOUT 5%-10% BY WEIGHT OF ANHYDROUS TETRASODIUM PYROPHOSHATE, SAID DETERGENT WHEN USED HAVING BOTH WATER SOFTENING AND ABRASIVE PROPERTIES RESULTING FROM THAT PORTION OF THE CRYSTEALLINE SODIUM METAPHOSPHATE WHICH IS NOT DISSOLVED WHILE THE PRODUCTS IS BEING USED. 